From 745ff14e6e1b88f04eb447d4883fab81650f745f Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 16 Oct 2019 17:11:56 +0200 Subject: [PATCH] [gdb/tdep] Fix 'Unexpected register class' assert in amd64_push_arguments Atm, when executing gdb.base/infcall-nested-structs.exp on x86_64-linux, we get: ... FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-tc-tf: \ p/d check_arg_struct_02_01 (ref_val_struct_02_01) FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-ts-tf: \ p/d check_arg_struct_02_01 (ref_val_struct_02_01) FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-ti-tf: \ p/d check_arg_struct_02_01 (ref_val_struct_02_01) === gdb Summary === nr of expected passes 9255 nr of unexpected failures 3 nr of expected failures 142 ... The 3 FAILs are reported as PR tdep/25096. The 142 XFAILs are for a gdb assertion failure, reported in PR tdep/24104, which should have been KFAILs since there's a problem in gdb rather than in the environment. A minimal version of the assertion failure looks like this. Consider test.c: ... struct s { struct { } es1; long f; }; struct s ref = { {}, 'f' }; int __attribute__((noinline,noclone)) check (struct s arg) { return arg.f == 'f'; } int main (void) { return check (ref); } ... When calling 'check (ref)' from main, we have '1' as expected: ... $ g++ test3.c -g && ( ./a.out; echo $? ) 1 ... But when calling 'check (ref)' from the gdb prompt, we get: ... $ gdb a.out -batch -ex start -ex "p check (ref)" Temporary breakpoint 1 at 0x4004f7: file test.c, line 8. Temporary breakpoint 1, main () at test.c:8 8 { return check (ref); } src/gdb/amd64-tdep.c:982: internal-error: \ CORE_ADDR amd64_push_arguments(regcache*, int, value**, CORE_ADDR, \ function_call_return_method): \ Assertion `!"Unexpected register class."' failed. ... The assert happens in this loop in amd64_push_arguments: ... for (j = 0; len > 0; j++, len -= 8) { int regnum = -1; int offset = 0; switch (theclass[j]) { case AMD64_INTEGER: regnum = integer_regnum[integer_reg++]; break; case AMD64_SSE: regnum = sse_regnum[sse_reg++]; break; case AMD64_SSEUP: gdb_assert (sse_reg > 0); regnum = sse_regnum[sse_reg - 1]; offset = 8; break; default: gdb_assert (!"Unexpected register class."); } ... } ... when processing theclass[0], which is AMD64_NO_CLASS: ... (gdb) p theclass $1 = {AMD64_NO_CLASS, AMD64_INTEGER} ... The layout of struct s is that the empty field es1 occupies one byte (due to c++) at offset 0, and the long field f occupies 8 bytes at offset 8. When compiling at -O2, we can see from the disassembly of main: ... 4003f0: 48 8b 3d 41 0c 20 00 mov 0x200c41(%rip),%rdi \ # 601038 4003f7: e9 e4 00 00 00 jmpq 4004e0 <_Z5check1s> 4003fc: 0f 1f 40 00 nopl 0x0(%rax) ... that check is called with field f passed in %rdi, meaning that the classification in theclass is correct, it's just not supported in the loop in amd64_push_arguments mentioned above. Fix the assert by implementing support for 'AMD64_NO_CLASS' in that loop. This exposes 9 more FAILs of the PR tdep/25096 type, so mark all 12 of them as KFAIL. Tested on x86_64-linux. Tested with g++ 4.8.5, 7.4.1, 8.3.1, 9.2.1. With 4.8.5, 3 of the 12 KFAILs are KPASSing. Tested with clang++ 5.0.2 (which requires removing additional_flags=-Wno-psabi and adding additional_flags=-Wno-deprecated). gdb/ChangeLog: 2019-10-16 Tom de Vries PR tdep/24104 * amd64-tdep.c (amd64_push_arguments): Handle AMD64_NO_CLASS in loop that handles 'theclass'. gdb/testsuite/ChangeLog: 2019-10-16 Tom de Vries PR tdep/24104 * gdb.base/infcall-nested-structs.exp: Remove XFAIL for PR tdep/24104. Add KFAIL for PR tdep/25096. Change-Id: I8b66345bbf5c00209ca75b1209fd4d60b36e9ede --- gdb/ChangeLog | 6 ++++++ gdb/amd64-tdep.c | 3 +++ gdb/testsuite/ChangeLog | 6 ++++++ .../gdb.base/infcall-nested-structs.exp | 18 ++++++------------ 4 files changed, 21 insertions(+), 12 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3827c4d3235..eeba0eed17e 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-10-16 Tom de Vries + + PR tdep/24104 + * amd64-tdep.c (amd64_push_arguments): Handle AMD64_NO_CLASS in loop + that handles 'theclass'. + 2019-10-15 Andrew Burgess * linespec.c (decode_digits_ordinary): Update comment. diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c index 232d16d7345..9006ec0167a 100644 --- a/gdb/amd64-tdep.c +++ b/gdb/amd64-tdep.c @@ -978,6 +978,9 @@ if (return_method == return_method_struct) offset = 8; break; + case AMD64_NO_CLASS: + continue; + default: gdb_assert (!"Unexpected register class."); } diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 877d0deffef..3277ee30098 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2019-10-16 Tom de Vries + + PR tdep/24104 + * gdb.base/infcall-nested-structs.exp: Remove XFAIL for PR tdep/24104. + Add KFAIL for PR tdep/25096. + 2019-10-16 Tom de Vries PR testsuite/25059 diff --git a/gdb/testsuite/gdb.base/infcall-nested-structs.exp b/gdb/testsuite/gdb.base/infcall-nested-structs.exp index f5fbf44ed16..957eb31bdc2 100644 --- a/gdb/testsuite/gdb.base/infcall-nested-structs.exp +++ b/gdb/testsuite/gdb.base/infcall-nested-structs.exp @@ -132,16 +132,9 @@ proc run_tests { lang types } { continue } - if { $lang == "c++" - && ( ( [regexp "struct_01_0(1|2|3)" $name match] && [regexp "^types-(td($|-)|tl(|l)(|-tf|-td|-tld)$)" $types match] ) - || ( $name == "struct_01_02" && $types == "types-tfc" ) - || ( $name == "struct_01_04" && [regexp "^types-(tf($|-)|ti(|-tf|-td|-tld)$)" $types match] ) - || ( $name == "struct_02_01" && [regexp "^types-tf-t(c|s|i)" $types match] ) - || ( $name == "struct_static_02_02" && [regexp "^types-(t(f|d|ld)-t(d|l|ll)$|t(d|l|ll)$|t(c|s|i|l|ll)-td)" $types match] ) - || ( $name == "struct_static_02_03" && [regexp "^types-(ti-t(f|l|d|)|tf(-|$)|ti$)" $types match] ) - || ( $name == "struct_static_04_02" && [regexp "^types-(t(c|s)-tf|tf-ts)" $types match] ) - || ( $name == "struct_static_06_04" && ![regexp "^types-(t(c|dc|ldc|ld)$|t.-tld|tl(l|d)-tld|t(f|d|ld)-tc)" $types match] ) ) } { - setup_xfail gdb/24104 "x86_64-*-linux*" + if { $lang == "c++" && $name == "struct_02_01" + && [regexp "^types-(tf-t(c|s|i)|t(c|s|i)-tf)" $types match] } { + setup_kfail gdb/25096 "x86_64-*-linux*" } gdb_test "p/d check_arg_${name} (ref_val_${name})" "= 1" @@ -154,8 +147,9 @@ proc run_tests { lang types } { set answer [ get_valueof "" "rtn_str_${name} ()" "XXXX"] verbose -log "Answer: ${answer}" - if { ($lang == "c++" && $name == "struct_02_01" && [regexp "^types-(tf-t(c|s|i)|t(c|s|i)-tf)" $types match] ) } { - setup_xfail gdb/24104 "x86_64-*-linux*" + if { $lang == "c++" && $name == "struct_02_01" + && [regexp "^types-(tf-t(c|s|i)|t(c|s|i)-tf)" $types match] } { + setup_kfail gdb/25096 "x86_64-*-linux*" } gdb_assert [string eq ${answer} ${refval}] ${test} } else { -- 2.30.2